SCIENCE CAPSULES

      It is a Sunday morning.  You are sitting in a easy chair with a news paper in one hand and a hot cup of coffee in another.  The tree lives are still.  No ripples in the nearby pond.  No traffic. And you think everything is at rest, quiet and still.  It is actually far from that.      When you lay still, you heart is throbbing 72 times per second pumping 2000 gallons of blood per day  through 60000 miles long blood vessels.  Your lung inhales and exhales air continuously.  And there are so many biological processes are ON in your body.     The liquid molecules in the hot coffee are at fast random motion.  The news paper you are holding is made up of hydrocarbon.  The electrons in these atoms are whirling around the nucleus and the protons are spinning.     Thousands of elementary particles called neutrino from cosmos are passing through your body at this instant. ...

    Consider a source of light like a candle.  The light (intensity) spread as the spherical wave .  We know  the brightness decreases as we move away from the candle.  We want to know exactly what is the intensity of the light  falling on the unit area at a particular distance from the source.  It can be obtained by dividing source's strength by the area of the sphere at that distance. Intensity on the unit area  = source's strength / area of the sphere                                         I=S/4𝚷R²                             R-Distance from source                                        I proportional  1/R²               sin...

    Water is a peculiar liquid.  But it is very essential for the life to beat.       When liquids are cooled down, they contract and become solid.  Water also contracts and become ice.  But it contracts up to 4 degree c only.  It expands from 4 degree c to 0 degree c due to water molecule bonding.  That is, its density decreases.  That is why ice floats on water.        In a water body like a lake, cooled water comes to the top because it is less denser.  Then the top surface first freezes over.  Since ice and water is poor conductor of heat, the liquid water remains intact below the friezed surface.  Hence the aquatic life can continue to live in the lake in winter also.  Men can walk and play on the lake during winter.   Even truck can move on it, if ice is sufficiently thick.      Iceberg is a ice mountain which has broken away  from glacier and f...

  Earth not only revolves around the sun but also tilts to one side or other every 6 months.   This tilting causes seasons .  The hemisphere which faces the sun is experiencing summer.  The other hemisphere which is away from the sun is having winter.      In summer, we want to cool our body.  Hence we use high speed fans which blow away hot air surrounding the body and brings in cool air.  In winter, we want to keep our body warm.  We wear woolen sweaters.  The hairy wool material traps warm air.  The air cannot easily escape from our body and hence keeps the body warm.      The earth is at right distance from the sun.  Hence it has the right temperature, not too cold or too hot.  The temperature keeps water in liquid form and sustain the life. Science update:  MIT  researchers made micro lenses with droplets.

  1 .       Mathematics of the pendulum is complicated. 2 .        Frequency of oscillation of a pendulum depends only on its length. 3 .       Time period or frequency does not depend on mass or material of the bob. 4 .         Pendulum’s energy alternates between potential and kinetic and hence it oscillates . 5 .        Potential energy and kinetic energy have opposite relationship and the total energy is conserved. 6 .         Tension along the string (upwards) and weight of the bob (downwards) are only the two forces acting in the pendulum. 7 .         Mainly gravity is responsible for the pendulum’s swings.  Hence ‘g’ can be measured with a pendulum. 8 .        Pendulum always tries to reach equilibrium (center position).  But overshoots it due to inertia 9 .   ...

  ELECTRONS AT WORK  Electron was discovered by J.J. Thomson  more than 100 years ago.  It is said to carry negative charge and negligible mass.  It is present in all the elements      When electron flows in a conductor, it is electric current.  We know, nothing serves like electricity.       Around the moving electrons magnetic field is formed and it gives rise to electromagnet.   When the electron oscillates electromagnetic waves like radio waves are radiated.  It is used for communication purpose.     While the electrons are moving in a conductor, they collide with the atoms and produce heat.  Many heating devices are made using this principle.  In atoms, when electron jumps from higher orbit to lower orbit, it loses energy in the form of light waves, X-rays etc,.   When the electrons moves in the magnetic field  at an angle, it experiences a force called Lore...

  Take a piece of salt harvested from ocean.  It  basically has cubical shape.  It is made up of sodium chloride molecules(NaCl).  The sodium and chlorine atoms are joined by ionic bond.  They are alternately arranged in rows, into planes and take the shape of cube.  We know sodium and chlorine are atoms that are made up of protons, neutrons and electrons.  Now they say, protons and neutrons are built from the particles called quarks.        Hence all non-life matters are made from fundamental particles like electron, proton etc,.  The particles constitute themselves into atoms.  Atoms are binded together to form molecules.  Molecules arranged themselves into some shapes or go shapeless like liquid and gas.        Life starts from non-life.  The atoms of some elements particularly carbon and hydrogen form complicated molecules.  The different set of molecules make plant ...

 Matter:  Electron is a particle and a book is a body made of particles. Waves:  Sound is a mechanical wave and light is a electromagnetic wave. Particles transport themselves and move in a straight line.  A wave is a disturbance or energy traveling through a medium or vacuum. A particle cannot deviate from its path without a force.  But waves from a source can spread in spherical form through all directions. A particle is characterized by its mass and speed .  Wave is characterized by frequency and wavelength . Waves can bend over the edges and spread through the hole.  But particles cannot do so. High frequency waves may behave like particles(light photons).  High speed particles may behave like waves(electron waves) . Matter can be converted into energy (waves) and vice versa, according to E=mc^2 Hence the border line between particle and wave blurs. Science update: US congress approves NASA manned mars mission by 2033. ...

  Take a strip of paper.  Give it a half twist and paste the ends.  It will look like a some twisted loop.  This is called mobius strip.      Now take a pen and draw a line at the centre of the strip.  If you go on drawing the line, you will come and meet the starting point of the line.  This indicates that this object has only one side or surface.  That is , two surfaces have become one long surface.        Now take a scissor, start cutting in the middle of the strip.  At the end, you will not get two half loops but two loops linked like a chain.  These are some peculiar properties of a mobius strip.  But there are some applications for this strange strip.        It is used as a conveyor belt so that  both the surface will be used evenly and as a result the belt will lost longer.  In computer printer, typewriter ribbons, recording tapes, this strip is used to us...

  Spherical shape :      When a clay like mass spins about itself(pot making), it is likely to attain spherical shape.  That is why all the celestial bodies are spherical.        All liquids have a property called surface tension.  That is, the liquids contract its surface area and try to occupy smallest area.  The sphere has a smallest surface area for a given volume.  Hence all liquid drops and water bubbles are spherical.        For the same reason, most fruits are spherical.  They try to contain good volume of food in efficient packages. Parabolic shape:      Parabolic mirrors efficiently reflects radiation as a parallel beam or focus the parallel beam of radiation to a point accurately.  Hence parabolic shape is used in antenna, telescope mirrors, car head light etc,.  Parabolic shape is also used in construction of buildings and bridges for its weight bearing...

      The force acting on unit area is called pressure.  Some times, we  want to know what is the pressure give by the atmosphere and it is easier to measure.        When we press on the head of the pin , we give force through the pin to its pointed end.  That is, we concentrate the force on very small area and there by increase the pressure.  Hence the pin easily pierces an object.  For the same reason, a knife cuts.      There are machines which produces jet of water with so much pressure that even cut metals.  Pressure does work.  So it is also a source of energy.   

     Physics says, when a force is applied on an object and it moves to certain distance, work is said to be done.  The capacity for doing work is energy.      A body at a height, can fall down due to gravitational force . So it said to posses 'potential energy'.        A fast moving body can hit another body and do some work.  So it has 'kinetic energy'.      Petrol can burn, produce heat, gases expand,  pushes the piston of an engine and does some work.  Hence petrol has 'chemical energy' (heat energy)      The chemical in the battery reacts and push the electrons from one electrode to another making electric current.  So the battery stores 'chemical energy'.      When light falls on certain materials, it ejects electrons.  So even light has energy      

      Earth attracts each and every body with gravitational force.  A freely falling body is continuously accelerated because gravitational force is continuously acting on it.  Gravitational force on a falling body is proportional to the body's mass.  Hence feather and boulder falls with same acceleration according to this formula g = f/m.  Hence  g = 9.8 m/s^2  is a constant near the surface of the earth.     The  g depends on the mass of  the celestial body.  g  is small on the moon.  So jumping will be very easy on the moon.  g is greater on Jupiter.  So even walking will be difficult on it 

          Force is not at all required for maintaining  the motion of  a body.  Force is only required to kick-start the movement, change the direction or accelerate the body.  But we are under wrong impression, because in our environment, air resistance and friction slows down the object.  To overcome these resistances, we are forced to apply force frequently.         Railway system use this principle for transportation(friction is greatly reduced in the tracks).  Planets and satellites go round for a long time without the use of force.  Scientists are trying to make a superconductor in which the resistance is totally eliminated and the current (electrons) will flow for ever .